This is a cross-sectional study comparing BMD in SLE and healthy subjects as assessed by three techniques: DXA,SEQCT, and Ultrasound. The goals are to establish normative data by age, gender and ethnicity; to evaluate BMD in SLE subjects; and to correlate BMD with clinical and laboratory disease characteristics in addition to skeletal and sexual maturation. The PCRC will be used for subject examination, nursing support, nutritional assessments, and data analysis.